Adhesion formation is a major problem following surgical procedures and is a frequent cause of postoperative pain and of infertility. Adhesions are the major cause of intestinal obstruction and it is estimated that following an intra-abdominal procedure, adhesions occur in some 50 to 80 percent of patients.
The mechanism of adhesion formation can be summarized as follows: a trauma of the peritoneal lining is rapidly followed by an inflammatory reaction; exudation of plasma, and deposition of a fibrin matrix. Subsequently the lesion is healed by the degradation of the fibrin deposition, and by proliferation of the mesenchymal lining of the peritoneum. If the repair process is not completed within a few days, fibroblast proliferation starts which ultimately will end in collagen deposition and adhesion formation. Key players in this process are in particular fibrin and fibrinolysis, macrophages and their secretion products such as growth hormones and cytokines, and obviously the epithelial repair process. From this repair process it results that adhesion formation is largely independent from the extent of the trauma.
Prevention of adhesion formation has been attempted mechanically and by modulating the inflammatory reaction. Mechanical adhesion prevention has been attempted by barrier methods and by the instillation of viscous fluids at the end of surgery keeping the surfaces separated, or recently by coating the surfaces by biodegradable gels.
These known approaches have been only moderately successful.